Synthesis of Pt-Loaded Y(2)WO(6):Eu(3+) Microspheres and Their Hydrogen-Sensitive Turn-Off Luminescence

[Image: see text] Pt nanoparticles were loaded on Y(2)WO(6):Eu(3+) phosphor microspheres to enhance hydrogen sensitivity at low temperatures through turn-off luminescence. Mesoporous Y(2)WO(6):Eu(3+) microspheres were synthesized first by a hydrothermal method. Pt loading on the surface of the Y(2)WO(6):Eu(3+) microspheres was then carried out by a method of the self-regulated reduction of surfactants using aqueous K(2)PtCl(4) solutions. Structural and morphological properties of unloaded and Pt-loaded Y(2)WO(6):Eu(3+) microspheres were investigated by various techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The relative photoluminescence intensity of the Pt-loaded Y(2)WO(6):Eu(3+) microspheres, due to (5)D(0) → (7)F(J) (J = 0, 1, 2, 3, 4) electronic transitions of doped Eu(3+) ions, was found to decrease as low as 22% after the microspheres were kept in the hydrogen gas atmosphere at a low temperature of 150 °C for 15 min. Meanwhile, mechanisms underlying this turn-off luminescence of the Pt/Y(2)WO(6):Eu(3+) microspheres in response to hydrogen gas are illustrated in detail.